Recursive AI

Parse a full name into first and last names in C#

OneContact is a free, open-source contact data library for .NET from Recursive AI. MIT or Apache-2.0, no native dependencies, no network access.

NuGet GitHub Docs Download example (.zip)

Split a full name into given, middle and family parts without treating every space as a field boundary.

Terminal
dotnet add package RecursiveAI.OneContact

Requires .NET 10 (net10.0); .NET 9 and earlier aren’t supported.

C#
using RecursiveAI.OneContact;
var name = PersonName.Parse(
    "Dr. Jane Alice Smith Jr.");
Console.WriteLine(name.Given);
Console.WriteLine(name.Family);
Text
Jane
Smith

Unzip the example, then dotnet run.

Full program

All sample input is written directly in the program.

C#
using RecursiveAI.OneContact;
 
var name = PersonName.Parse("Dr. Jane Alice Smith Jr.");
Console.WriteLine($"Given: {name.Given}");
Console.WriteLine($"Middle: {name.Middle}");
Console.WriteLine($"Family: {name.Family}");
Console.WriteLine($"Prefix: {name.Prefix}");
Console.WriteLine($"Suffix: {name.Suffix}");
Console.WriteLine($"Canonical: {name.Canonical}");

dotnet run prints:

Text
Given: Jane
Middle: Alice
Family: Smith
Prefix: Dr.
Suffix: Jr.
Canonical: Dr. Jane Alice Smith Jr.

PersonName.Parse throws ContactParseException for rejected text; ambiguous readings still need review rather than treating a successful parse as certainty.

Variations

Read a family-first name marked by a comma:

C#
using RecursiveAI.OneContact;
var name = PersonName.Parse("Smith, Jane Alice");
Console.WriteLine(name.Given);
Console.WriteLine(name.Middle);
Console.WriteLine(name.Family);
Text
Jane
Alice
Smith

The short answer

Use PersonName.Parse and read Given, Middle and Family. OneContact also keeps titles, particles, second family names, nicknames and suffixes in separate parts. The snippet at the top prints Jane and Smith, while the full program shows where Dr., Alice and Jr. went.

This is a rules-based reading of the supplied text, not a way to discover a person’s identity. The name parsing documentation states: “Nothing is inferred: no gender, origin or salutation, and no part is added that the text did not contain.” Keep the original full name if you need to let the person correct the result.

How do I split a full name into first and last names in C#?

Map Given to a first-name field and Family to a family-name field only when those fields fit the application. The parser has more parts than that pair because a name can contain more structure. A particle such as van der stays in Particle, separate from Family. A second family name can have its own part. Dropping all other parts just because an export has two columns loses information.

The variation uses a comma to mark family-first input: Smith, Jane Alice. The parsed parts are the same given, middle and family names as in given-first input. Canonical writes reading order, while Order remembers the input order. Canonical text is useful for display, but it is not a replacement for the source when the exact input matters.

A bare single word can be accepted by PersonName.Parse, with the SingleWord flag. That does not supply a missing surname. Don’t fill an absent family name by copying the given name or by guessing from an email address. The output can only describe what the input supports.

How do I parse first, middle and last names in C#?

Read Middle explicitly instead of appending every word after the first to the family name. The full program shows all three fields from a single synthetic input. Prefixes and generational suffixes are separate again, so they do not have to be manually removed before parsing.

Supply country and language hints with NameHints(Region? country, string? language) to choose between readings left open by the text. The documented examples include Hungarian family-first order and Spanish-style second family names. A hint never overrules the text. Supply hints from known context, not from the current process culture: OneContact results do not depend on CultureInfo.

Casing restoration applies when the whole input is one case. Mixed-case text stays as written. This is a rule-based transformation, not proof that the resulting spelling is the person’s preferred spelling. In an editable form, show the result as a suggestion and preserve a path to correction.

What are common mistakes when parsing names?

A space split confuses particles, titles, suffixes and compound forms with field boundaries. Assuming every input is one person is another mistake: use NameParsing.Classify and NameParsing.SplitMany to classify the input and split multiple people. For a person field, reject or review text that represents a company or several people instead of silently storing the first chunk.

Comparison is a separate decision. PersonName.Key aggressively folds parts and some nicknames; it is not the canonical display name. The person key notes document exactly what is lost. Use that key for candidate matching, not to overwrite the name the person supplied.

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